SPL Audio Crescendo duo v2 Dual-Channel Microphone Preamplifier with 120V Technology

Crescendo duo combines the precise sound that German Rundfunk-Technik is famous for with the innovative SPL 120V technology.

The internal operating voltage of 120 volts allows Crescendo microphone preamplifiers to break completely new ground. This results in microphone preamps that sound detail-rich, vivid and equally honest.

Crescendo duo lets microphones shine in a whole new light – because they have never been amplified like this before.

• The Undistortable
Thanks to the SPL 120V technology, it is almost impossible to overdrive this microphone preamplifier.

Crescendo duo is a dual-channel microphone preamplifier with 120V technology.

Both channels feature the same range of functions. Besides phantom power (48 V) for condenser microphones, polarity reversal, a high-pass filter and a PAD switch, they provide the possibility to adjust the VU meter to display very high levels – so they leave nothing to be desired. The gain can be adjusted comfortably and precisely via a 12-step switch. With the switchable output control, the output level of the Crescendo duo can be perfectly adapted to following AD converters. Two outputs per channel allow the signal to be sent to two different devices in parallel. In addition to the extensive feature set and the outstanding technical characteristics, Crescendo duo convinces with a sonic authenticity that is second to none.

• The 120V technology
The 120V technology is our reference technology. The 120V technology is unique in the world. It operates at a DC voltage of 120 volts. This is four times that of IC-based semiconductor op-amps.

The 120V technology works with +/-60 V. To be able to handle such a high voltage, we have developed special proprietary operational amplifiers that can operate with a DC voltage of +/-60 V: the SPL 120V SUPRA operational amplifiers. This high voltage would destroy conventional components and operational amplifiers.

The 120V technology achieves exceptional technical specifications and sonic benefits. Technically, in terms of dynamic range, signal-to-noise ratio and headroom. Sonically, in terms of richness of detail and an absolutely relaxed listening experience.

By the way, the “120V” in the name of the technology has nothing to do with the local mains voltage from the mains power socket. This is about the operating voltage inside the device with which the audio signals are processed.

The mains voltage from the mains power socket is transformed to the required secondary voltage in the device’s internal linear power supply with toroidal transformer. Rectifiers convert this AC voltage into DC voltage required in the audio device.

The idea for SPL 120V technology and the SUPRA operational amplifier based on this technology were developed in the 1990s by SPL founder and chief developer Wolfgang Neumann.

With the goal of building the best mastering console ever, this basic technological philosophy then took shape for the first time – thus the SPL MMC1 Mastering Console for Galaxy Studios saw the light of day in 2000.

• Looks great, feels great – and lasts for a lifetime
The Crescendo duo has a 4 mm thick, black anodized aluminum front panel and aluminum knobs milled from solid. The housing is made of high-quality steel and is powder-coated in elegant black.

• Sounds good
With all SPL devices we develop not only according to plan, but also by ear. Many important components are installed on the circuit boards using Through-hole technology. This way we can ensure that we can use the best sounding components.

Analog input & output; XLR (balanced)
• Maximum output level: 32.5 dBu
• Input impedance: 10 kΩ
• Output impedance: 75 Ω
• Frequency range (50 dB Gain, -3dB): 20 Hz – 100 kHz
• THD + N (10 Hz – 22 kHz, 30 dB Gain): 0.0036 %
• THD + N (10 Hz – 22 kHz, 70 dB Gain): 0.32 %
• Noise (A-weighted, 150 Ω, 30 dB Gain): - 89.2 dBu
• Noise (A-weighted, 150 Ω, 70 dB Gain): - 51.7 dBu
• Equivalent Input Noise (EIN, 70 dB Gain, 150 Ω): -121.7 dBu
• Common mode rejection (1 kHz, 30 dB Gain): 79 dB

Internal Linear Power Supply with Shielded Toroidal Transformer
• Operating voltage for audio electronics: +/- 60 V
• Operating voltage for relays and LEDs: + 12 V

Mains Power Supply
• Mains voltage (selectable, see fuse chamber): 230 V AC / 50; 115 V AC / 60 Hz
• Fuse for 230 V: T 0.5 A
• Fuse for 115 V: T 1 A
• Power consumption: max. 17.7 VA

Dimensions & Weight
• W x H x D (width x height x depth): 482 x 88 x 300 mm
19 x 3.46 x 11.8 inch
• Unit weight: 6.1 kg
13.45 lbs
• Shipping weight (incl. packaging): 7.5 kg
16.54 lbs